There is a swaying motion in my cars rear end. the faster it goes the worse it gets. I have only had my Imp. for about a year. Not sure if there are sway bars or what in the rear end. Any sugestions would help. Thank you!!
You might also just check tire pressure. I can think of at least two times when I thought..."Whoa, somethings wrong this car is really squirrely in the back end." and it turned out to be low tire pressure. Hopefully it's something easy like that.
If it is doing this also at slow speeds in a straight line you may thrown a belt in a tire.
Jack the car up and spin the rear tires while watching the treads.
Just one more idea to add to the good possibilities posted already.